The week in pictures: 23 March 2012

A double rainbow arches over Denver, Colorado in this picture captured by amateur photographer Greg Thow, 47. He rushed up 20 flights of stairs of an observation tower to bag the photo. He says: "The elevator was not operational so to get to the top of the tower you have to take 20 full flights of stairs. The climb was exhausting. My phone was ringing repeatedly but I was determined to get to the top and figured I'd call whoever it was after. When I finally got to the top and opened the door the rainbow was the first thing I saw. I actually did gasp for a second, then rushed to set up my equipment before it faded away. The phone calls turned out to be numerous folks calling me to tell me about the rainbow since I lived downtown and were wondering if I'd seen it."Picture: GREG THOW / CATERS NEWS